1. Field of the Invention
The present invention relates to an optical communication module and a method for making an optical communication module.
2. Description of the Related Art
Techniques for transmitting signals by using light as carrier wave are widely used. Optical communication modules are used for these techniques, an example of which is disclosed in Patent Document 1 (Japanese Patent No. 4406447). The optical communication module disclosed in this document includes an optical semiconductor element, which may be a light-emitting element or a light-receiving element. Optical fibers are used for transmitting light from a light-emitting element or transmitting light to a light-receiving element. In the disclosed optical communication module, the optical semiconductor element is attached to an optical fiber holder, with the optical function region of the optical semiconductor element, which performs light-emitting function or light-receiving function, exposed. Optical fibers are attached to the optical fiber holder of the optical communication module in such a manner that the end surfaces of the optical fibers face the optical function region.
In this Patent Document 1, the optical fiber holder is used for properly positioning and fixing the optical fibers with respect to the optical semiconductor element. The optical fiber holder has an opening which is open at the front end and the rear end of the holder. The optical semiconductor element is attached to the front end of the optical fiber holder, with the optical function region facing the opening, so that the optical function region is exposed from the rear end of the optical fiber holder through the opening. The optical fibers are inserted into the opening from the rear end and positioned with respect to the optical function region. In inserting the optical fibers, a resin that transmits light emitted from or to be received by the optical function region is poured into the opening. By this, the optical fibers are fixed, and the gaps between the optical function region and the optical fibers are filled with the resin. The optical fiber holder, which holds the optical fibers and the optical semiconductor element, is mounted on a substrate, along with a component such as a control IC for the optical semiconductor element, whereby the optical communication module is completed.
To protect the component such as a control IC, a cover case or a sealing resin for covering the control IC needs to be provided. To realize a low manufacturing cost and size reduction, the use of a sealing resin is preferable. However, it is difficult to provide a sealing resin so as not to cover the optical fibers. To efficiently manufacture the optical communication module, the components of the optical communication module need to be mounted collectively on a substrate. However, when the space for arranging the optical fibers is secured, it is difficult to mount the components at a high density.